HP Z440 700W PSU max PCIe wattage

[z440_user_937]

Quick question about the 700W PSU on the hp z440 workstations. Looking to upgrade my current k2200 to an rtx 40xx (4070 or above) when they release next year. Biggest issue blocking me right now is the 225W cap HP has said the z440 workstation has on gpu power.

Looking at the sticker / amperage ratings on the PSU itself it seems to support much more than what HP has rated it for, with each 6 pin connector being rated for 12v@18A, implying that I should be able to use a 6pin to 8pin connector and be well within spec of the PSU, while drawing 150W. Overall system draw will not cross 700W, under full load I would expect it to be in the neighborhood of ~650W. Does anyone have any experience running a 300w+ gpu on the hp z440 system OR am I misunderstanding the label / is it incorrect.
[Link for PSU label, its the third image in the gallery] https://www.pchub.com/hp-z440-workstation-server-power-supply-700w-dps-700ab-1-a-719795-003-809053-0...

I don't really care about warranty given that I bought the workstation second hand and it's pretty old now, I also recognize that the official answer is no, but if I'm understanding the label correctly it should be theoretically possible and within the power supplies limitations; I'm more concerned about:

1) Damaging the PSU / components downstream
2) Fire hazards

I've upgraded to a 2696v3 that I got pretty cheap and use the machine primarily in GPU accelerated tasks, hence why I don't care that much about cpu bottle-necks. Hard bent on upgrading to a high tier 40xx gpu that passes the 225W threshold, so if I'm unable to do that with this machine, I'll probably end up building a completely new one, which I kinda wann avoid.

Appreciate any guidance

[NonSequitur777]

@z440_user_937,

Welcome to our HP User Forum!

As I understand it, the (Nvidia) 12-pin PCIe power cable is supposed to deliver up to 600 watt, and I quote:

"Nvidia's 12-pin power connector (formally known as the Molex MicroFit 3.0 dual row, 12 circuits) is designed to deliver up to 600W to a graphics card using 12V rail of a PSU and apparently the same amount of power is set to be delivered by a 12+4-pin auxiliary PCIe 5.0 power connector (also known as 12VHPWR)."

Link: https://www.tomshardware.com/news/nvidias-12-pin-power-connector-will-work-with-next-gen-pcie-5-psus

 See also: https://videocardz.com/newz/pci-express-gen5-12-pin-power-cable-looks-just-like-nvidias

This would suggest that a 12-pin to ATX Dual 6+2-pin splitter cable, such as this one: https://www.amazon.com/12Pin-Splitter-Graphics-Modular-Cable/dp/B08PFHVZTS, may not provide sufficient power for an RTX 40xx card, even with 2 x (12v * 18 A) 6-pin cables:

Hope this was helpful.

Kind Regards,

NonSequitur777

[BeemerBiker]

Please read the following discussion about 440 power upgread

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Need-to-change-PSU...

The latest info on the 4000 series indicates lower power requirements than originally released

https://screenrant.com/nvidias-rtx-4000-series-lower-power-requirements/

That being said, it is important to note that power supplied to the PCIe card from the motherboard is specified as 75 watts max according to PCI express standards. Any extra power requirements will come via the power connectors.  The 440 motherboard is spec'ed per PCI standards.   I suspect the 4000 series should be matched up against a recommended ATX power supply and not the 700 watt regardless of how good it is.  This is my 0.02c opinion

[edit] @NonSequitur777 you beat me to it!

[NonSequitur777]

@BeemerBiker,

Yes, power requirements for the 40xx series may be less (emphasis added) -better to wait, I imagine, or at least be ready to upgrade your power supply.

Kind Regards,

NonSequitur777

[z440_user_937]

Yup, I think that even though the 12 pin connector supports up to 600W the GPUs will draw nowhere near that, looking at 
https://www.techpowerup.com/gpu-specs/geforce-rtx-4080.c3888

 it is speculated that the 4080 will draw ~340W, so even if it uses a 600W connector it should only draw a sustained 340W.

My main question was whether or not the PSU could even supply power past 225W. The PSU label implies it definitely can, but hp says differently, and it seems weird they would undersell their component by such a large degree.

Anything past a 4080 would require a power supply upgrade for sure though, and since the PSU's in the hp440 are proprietary I don't want to have to drill holes to mount an ATX PSU.

[NonSequitur777]

@z440_user_937,

In my experience, HP likes to play it (very) safe as a matter of principle.

I would have confidence that your PSU's 6-pin PCIe power cables + PCIe x16 slot are capable to provide at least 450 watt total without even breaking a sweat.

The reason why I am quite confident stating this, is after looking at your 700 watt power supply's specs, HP p/n: 758467-001 [alternatively p/n: 792339-001 or: 809053-001] -"Power supply - Rated at 700 Watts, 90% efficient rating - Specifications include Wide-ranging, active Power Factor Correction (PFC) - Energy Star qualified (configuration dependent), 100–240 VAC input", which is actually a really nice high-end PSU.

Kind Regards,

NonSequitur777